Integrated circuit chips use power supplies to convert an input voltage from a power source to an output voltage across an output load. Typically, such power supplies are regulated in order to maintain a constant output voltage across the output load even if the output load changes and/or the input voltage varies.
Linear regulators are often used to provide this regulation. Linear regulators continually adjust a voltage divider network in order to maintain a constant output voltage. The difference between the input voltage from the power source and the output voltage across the load is dissipated as heat. Thus, linear regulators are not an efficient way to provide regulation of a power source unless the output voltage is very similar to the input voltage.
Switched mode power supplies utilise a different mechanism to provide the regulation. A switching arrangement is provided between the power source and the output load. The switching arrangement continually switches ON and OFF. In the ON state, the power source is connected to the output load. In the OFF state, the power source is not connected to the output load. The duty cycle (proportion of ON time) is selected in order to achieve the desired output voltage. Excess energy is stored in the circuit until it is released to the output load. Thus, switched mode power supplies are more efficient than linear regulators at regulating the supply of power from a power source to an output load.
It is known to utilise switched mode power supplies in integrated circuit chips to supply power to a plurality of output loads. These output loads may have different power requirements to each other. Additionally, power management considerations in integrated circuit chips are becoming increasingly important as the market demands greater functionality at lower power consumption rates. Thus, the power requirements of each output load may vary over time. Thus, there is a need for a power supply regulation system having a responsive control system to the power requirements of multiple output loads.